Storage controller and storage control method

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EP 2 239 655 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	03.11.2010 Bulletin 2010/44

(43)	Date of publication A2:
	13.10.2010 Bulletin 2010/41

(21)	Application number: 10168362.1

(22)	Date of filing: 10.10.2007

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International Patent Classification (IPC):

G06F 3/06^(2006.01)

(84)	Designated Contracting States:
	DE FR GB IE
	Designated Extension States:
	AL BA HR MK RS

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Priority:

13.12.2006 JP 2006335903

(62)	Application number of the earlier application in accordance with Art. 76 EPC:
	07254024.8 / 1936488

(71)	Applicant: Hitachi Ltd.
	Tokyo 100-8280 (JP)

(72)	Inventors:
	Seki, Toshiya Tokyo 100-8220 (JP) Katsuragi, Eiju Tokyo 100-8220 (JP) Sakaguchi, Takashi Tokyo 100-8220 (JP)

(74)	Representative: MERH-IP Matias Erny Reichl Hoffmann
	Paul-Heyse-Strasse 29 80336 München 80336 München (DE)

(54)	Storage controller and storage control method

(57) A storage control technique with which, even if not data, but only its management information is deleted, a host system can recognize storage areas storing unnecessary data and so use them effectively. When a file system in the host system deletes the management information for data stored in a page in a pool volume, a control circuit writes '0' in all the areas in the deletion target page in response to a command from the host system. The control circuit then detects the page where '0' is written in all of its areas and releases it from allocation to the corresponding virtual volume.

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